9404089 Freire The research covers topics concerned with the spectrum of the Laplacian on complete non-compact Riemannian manifolds, mainly in the case of nonnegative curvature. Asymptotic methods are expected to give new results concerning the spectral analysis of harmonic differential forms. The Yang-Mills flow technique will also be studied to determine uniqueness of solutions of partial differential equations. The research has potential applications to mathematical physics, in particular, gauge field theory. ***